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    Karyomorphological features of Turkish Centaurea (subgenus Cyanus, Asteraceae) species and its taxonomic importance
    (TUBITAK SCIENTIFIC & TECHNICAL RESEARCH COUNCIL TURKEY, 2019) Şirin, Emrah.; Bozkurt, Meryem.; Uysal, Tuna.; Ertuğrul, Kuddisi.
    In this study, the karyomorphology of 20 Turkish Centaurea (subgenus Cyanus) taxa was examined. The number of chromosomes of 11 taxa belonging to the subgenus Cyanus was determined for the first time. As a result of the karyomorphological studies, the number of basic chromosomes was determined to be x = 8, 10, and 12 in annuals and x = 10 and 11 in perennials. The populations are tetraploid in the seven perennial taxa and polyploidy is not rare for this group. On the other hand, all annual taxa are diploid. Considering the asymmetry indices, we can conclude that most taxa have symmetrical karyotypes. The most common karyotype formulas are 40 metacentric chromosomes (m), 20m, and 16m + 4 submetacentric chromosomes, respectively. A satellite was detected in the majority of the taxa, but it was observed to be mainly localized on the short arm of the chromosome. Satellites are located mainly on the second chromosome.
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    Pollen morphology of section Cheirolepis Boiss. of the genus Centaurea L. (Asteraceae) in Turkey
    (BANGLADESH ASSOC PLANT TAXONOMISTS, 2019) Citak, Burcu Yilmaz.; Dural, Hüseyin.; Uysal, Tuna.; Pinar, Nur Münevver.
    In this paper, the palynomorphology of 17 taxa of section Cheirolepis in Turkey, were investigated by light (LM) and scanning electron microscope (SEM). Detailed descriptions of the pollen grains were given for each taxon and a well-resolved dendrogram was generated through numerical analysis of palynological diagnostic features. The pollen grains were found to be radially symmetric, isopolar, and generally 3-zonocolporate, with the exception of C. derderiifolia, C. kotschyi var. floccosa, and C. saligna, which were also 4-zonocolporate. The shape of the pollen grains were prolate-spheroidal, with the polar axes of 32.76-46.26 mu m and equatorial axes of 31.86-45.82 mu m. The sculpturing of the pollen grains was generally scabrate-perforate or rarely microechinate-perforate. The spines were conical with a changing base length. The length and the width of the spines varied between 0.48 and 2.28 mu m and 0.4 and 3.39 mu m, respectively. The number of perforations at the base of the spines ranged in two or more rows and they varied between 5 and 30. The number of spines was 16-70 in 10 mu m(2). The results of this study showed that the polar axes, equatorial axes, aperture type, pollen shape, spine length, perforation number, and number of spines in 10 mu m(2) are essential for distinguishing the studied taxa. The taxa were grouped by clustering analysis of selected pollen characters using the UPGMA method.